I am new into Modelica/Dymola-modeling. I started to model fluid models for my master-thesis (pipes, heaters, control). My professor suggested: Check the eigenvalues of the systems and the ratio of them (and if the systems is stiff). So did the following:
- Linear analysis
- Full linear analysis
- SimulationSetup: linearizeAtInitial = false; t_linearize = 1000 (that the system is in operation mode (after initialization)
The simulation restuls are Ok.
But the linear analysis says: The system is not stable --> what does that mean?
And regarding eigenvalues i get the following result:
I have to say that I am not really into numerics. So these are my questions:
- Does that mean that the system has 23 eigenvalues?
- If I want to specify how "stiff" the system is, I guess i have to check the biggest and smallest value?
- What are the eigenvalues 12-23 --> not stable, not stabilizable, not detectable?
Any recommendations for a (simple) introduction book/chapter that explains general things like :linearication of Models, eigenvalues, etc.?
Thank you very much for your help.